Crop yield and optimized N fertilization in a changing climate

Background and Objective

In addition to the greenhouse gas emissions from the production of fertilisers, the N2O emissions that occur on agricultural land, mainly as a result of unused N fertilisers, contribute to the climate impact of plant production. Optimal fertilisation, which corresponds to the actual nutrient requirements of the plants, is essential both in terms of climate and water protection. However, the increasingly unfavourable weather conditions are making this need-based fertilisation increasingly difficult. As climate variability increases, yield variability may also increase, increasing the risk of underutilised N.

Approach

The consortium of partners from the Thünen Institute and the Julius Kühn Institute investigated how climate change is affecting nitrogen use and how fertilisation can be further improved under these conditions. For this purpose, historical Germany-wide operating data on yields and nitrogen fertilisation are analysed with special consideration of extreme weather influences. By means of process-based agro-ecosystem models, various N-fertilization strategies and other adaptation strategies such as variety selection under climate change conditions for relevant cultivation regions in Germany will be examined by the end of the century and used for the analysis of operational risk management. The aspects of late fertilisation and quality are also analysed. The synthesis of the analyses allows new insights into optimal fertilisation strategies and nitrogen use efficiency under climate change conditions, which are also of great relevance for emission reporting.